Telescoping members are commonly used as a means for providing adjustability for a variety of applications. Telescoping legs are known for use with camera tripods and the like. They are likewise known for use as elongated handles to permit items such as ceiling painting apparatuses or light bulb changers to be manipulated at locations which would otherwise be beyond the reach of the operator.
A common problem associated with telescoping members has been the relatively expensive and sometimes cumbersome locks which are used to hold the telescoping members in a longitudinally fixed relationship after the telescoping members are adjusted to the desired length. Sometimes means used for this purpose have involved a plurality of pairs of transversely aligned holes along the longitudinal sidewall of the first telescoping member, and a pair of corresponding transversely aligned holes in the second telescoping member. As the two telescoping members are moved longitudinally with respect to each other, one of the pairs of aligned holes of the first telescoping members aligns with the pair of holes from the second telescoping member. Typically, a bolt or securing pin is received through the aligned pairs of holes to secure the first and second telescoping members in fixed telescoped position.
Nevertheless, it is often difficult to adjust the length of members provided with this type of fastening means. A user must align the appropriate holes and reinsert the pin at the chosen location. Two hands are often required and several "trial and error" efforts may be necessary. The tolerances provided between the holes and the pin frequently ensure that the point where the members are secured together will be loose and are likely to result in considerable undesirable "play" between the members at this location.
Another approach to releasably locking relatively telescoped members involves compressing an outer tubular member against the inner member at the entrance end of the outer member. The outer tube has longitudinal slots to permit the tube to be squeezed to a smaller effective diameter. The threaded outer surface of the outer member adjacent the joint is tapered and receives a threaded nut which may be manually manipulated up and down the threads to tighten or loosen the compressive force on the inner member. This fastening means is expensive because of the machining required to present the threaded taper. Further, it usually requires a number of turns of the nut to move the lock from its fully closed to its fully open position. Only the outermost tips of segments defined by the slots bear against the inner member, making the fastening inherently relatively weak.